1. Field of the Invention
The present invention relates to a system useful for applying traction to the cervical spine. More specifically, this invention relates to a headgear or harness useful in a cervical traction system.
2. Brief Description of the Prior Art
Cervical traction is widely accepted as an effective nonoperative treatment of patients with cervical spine disorders such as: 1) cervical spondylosis (arthritis); 2) displacement of intervertebral disc; 3) nerve root compression; and 4) post traumatic derangements. Very often, severe neck pain, limb pain or headaches are associated with these disorders. In each of these cases, cervical traction is applied to provide joint separation, decompression of nerve impingement, neck immobilization, stretching and/or mobilization of the neck muscles.
Ideally, cervical traction for therapeutic purposes should engage only the cervical area and should avoid any painful or damaging involvement of the chin, the mandibular joints, or the temporal areas of the skull. In practice, however, prior art attempts at securing a traction device to the skull have been largely unsuccessful in avoiding such pain or damage.
The headgear used in existing cervical traction devices falls into four basic categories: 1) the "crown" halters; 2) the "chin strap" halters; 3) the track mounted devices; and 4) the skull penetrating devices.
The "chin strap" devices consist of various types of head halters that use chin straps to allow a secure attachment platform for the applied traction. Although these devices are simple in design and relatively inexpensive, the traction forces applied thereto transfer a significant pressure from the chin, directly to the temporomandibular joint. Since pressure at this joint is painful, the patient's tolerance for pain is a limiting factor that determines the amount and duration of traction that can be applied. Typically, the maximum tolerable traction force is about 20 pounds, which is often insufficient for effective separation of the cervical vertebrae. Moreover, severe permanent damage of the temporomandibular joint may occur, resulting in prolonged local pain and/or headaches, and even the need for corrective surgery in some instances.
The "crown" halters are bandage-like devices that cover the ears, the back of the skull, and may also cover the forefront of the head. Traction is applied to the device at a location near the base of the skull.
The main disadvantage of this type of device is the need for an extremely tight attachment to the head before the device is capable of applying traction forces thereto sufficiently great for effective treatment. This extremely tight attachment to the head can cause pain in the form of headaches, etc. Adjusting the tightness for comfort, limits the traction force to values (only up to about 15 lbs.) that are often insufficient for effective treatment. Also, this type of traction device does not permit axial traction to be applied to the patient because of its tendency to slip off the user's head under such forces.
The skull penetrating devices are used in severe neck injuries that require continuous skeletal traction such as for immobilization in fracture cases. The traction forces are applied on various types of tongs that penetrate into the skull, or onto a "halo ring" attached directly to the skull.
The track mounted devices consist generally of two V-shaped arms mounted on a sliding carriage. The V-shaped arms support the back part of the head, with a forehead strap forcing the head into the V-shaped arms. The traction is applied by sliding the V-shaped arms on a fixed track mounted on a bed frame. Movement of the V-shaped arms along the track causes extension of the cervical spine. Compared to the above-mentioned traction devices, the track mounted device is more commonly tolerated by patients, and permits higher amounts of traction force without causing trauma to the chin, forehead or occipital regions of the head. However, the track mounted devices are relatively expensive and cumbersome and do not allow for any type of head rotation. These devices are also unsuitable for other than institutional therapy.